feat: add http as smtp provider (#8545)

# Which Problems Are Solved

Send Email messages as a HTTP call to a relay, for own logic on handling
different Email providers

# How the Problems Are Solved

Create endpoints under Email provider to manage SMTP and HTTP in the
notification handlers.

# Additional Changes

Clean up old logic in command and query side to handle the general Email
providers with deactivate, activate and remove.

# Additional Context

Partially closes #8270

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Co-authored-by: Livio Spring <livio.a@gmail.com>

pkg/grpc/settings/settings.go

@@ -1,3 +1,5 @@
 package settings
 
 type SMSConfig = isSMSProvider_Config
+
+type EmailConfig = isEmailProvider_Config